429 Too Many Requests

Problem/Motivation

I’m seeing the error come through my logs:
RequestException: 429, Too Many Requests, Client error: `POST https://authz.constantcontact.com/oauth2/default/v1/token` resulted in a `429 Too Many Requests` response

This makes sense given Step 8: Refresh the Access Token of the API Docs says this:

Constant Contact rate limits the Token endpoint. A 429 response will likely be returned if you attempt to refresh an access token before every V3 API request. Constant Contact recommends that you only send a refresh token request to get a new access token if your existing access token is expired or about to expire.

Line 995 of src/Service/ConstantContact.php does exactly that.

Steps to reproduce

Check the logs of a site with a high trafficked site.

Proposed resolution

Probably need to move the refresh token into cron and have some sort of expiration check.

Remaining tasks

User interface changes

API changes

Data model changes